Heat-treated NiTi instruments and final irrigation protocols for biomechanical preparation of flattened canals

Abstract

This study evaluate shaping ability of heat-treated NiTi-alloy instruments associated with different final irrigation protocols in flattened root canals. Thirty human mandibular incisors with flattened root canals were divided into 5 groups (n = 10): (XP) Original Protocol XP-endo Shaper; (XP-WT) Original Protocol XP-endo Shaper with working time variation; (XP-K) XP-endo Shaper with kinematics variation; (XP-WTK) XP-endo Shaper with kinematics and working time variations; (Hyflex) Hyflex CM. For the variation in working time protocols the same sample of the XP-endo Shaper groups with and without kinematic variation were used. To evaluate final irrigation protocols, groups 1, 3 and 5 were submitted to 3 protocols: (NI) No irrigation (n = 2); (CI) conventional irrigation (n = 4), and (EndoVac) irrigation (n = 4). The samples were scanned by microcomputed tomography and prepared for scanning electron microscopy evaluation. Quantitative data were evaluated using the parametric ANOVA test, with statistical significance level set at 5%, and qualitative data obtained were compared to establish the agreement between examiners through the Kappa test. It was observed that in the analysis of XP-endo Shaper protocols, the additional working time did not cause difference in any of parameters evaluated (p > 0.05) in relation to time recommended by manufacturer. Compared to Hyflex, XP-K showed highest mean volume increase (p < 0.05) and lowest percentage of untouched walls (p < 0.05). In the qualitative evaluation, final irrigation protocol with EndoVac provided the best cleaning results when associated with XP-K and with Hyflex. Thus, supplementary techniques are effective tools to enhance cleaning and to promote higher touch of walls during root canal preparation.

Optimization of automated preparation of long oval-shaped root canals using supplementary instrumentation

“…Different techniques and instruments have had difficulties in preparing root canals as untouched areas are always left after instrumentation 2 , 4 , 5 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 . The present study assessed XP-endo Shaper and WaveOne Gold systems before and after additional manual instrumentation in the preparation of long oval-shaped root canals.…”

“…Several automated systems have been proposed and their mechanical action is responsible for about 97% of the bacterial reduction within the root canal 1 . However, anatomical complexity is a problem as the preparation of non-round root canals is more difficult 2 , 3 , 4 , 5 . This difficulty could result in the failure of the endodontic treatment 6 .…”

“…In general, both systems leave untouched areas within the root canal (5,8-14). Changing the kinematics of the automated systems was proposed to increase the overall prepared surface of the root canal 15 , however, Carvalho et al 5 found no difference in the XP-endo Shaper by using protocols with and without brushing motion to improve the preparation of the flattened root canals. Other authors proposed a supplementary instrumentation after automated preparation because it increased the area of touched walls within non-round root canals 4 .…”

Cleaning and Disinfecting Oval-Shaped Root Canals: Ex Vivo Evaluation of Three Rotary Instrumentation Systems with Passive Ultrasonic Irrigation

“…However, XPS stands out with its envelope of motion, which enables it to adapt more effectively to the morphology of root canals. Overall, these three systems possess distinct characteristics for preparing root canals [ 16 , 17 , 18 , 19 , 20 ]. However, to date, there is no study that compares the effectiveness of these systems in cleaning and disinfecting oval-shaped root canals.…”

“…During mechanical instrumentation of the root canal system, a smear layer or hard tissue debris can form on the root canal walls, potentially harboring bacterial pathogens and hindering disinfection, ultimately compromising the quality of the root canal sealing and obturation [ 20 ]. To improve the effectiveness of rotary instruments, endodontic irrigants such as sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are frequently used in root canal treatment, with passive ultrasonic irrigation (PUI) techniques employed to activate the irrigants.…”